FFmpeg
tmv.c
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1 /*
2  * 8088flex TMV file demuxer
3  * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * 8088flex TMV file demuxer
25  * @author Daniel Verkamp
26  * @see http://www.oldskool.org/pc/8088_Corruption
27  */
28 
30 #include "libavutil/intreadwrite.h"
31 #include "avformat.h"
32 #include "internal.h"
33 
34 enum {
35  TMV_PADDING = 0x01,
36  TMV_STEREO = 0x02,
37 };
38 
39 #define TMV_TAG MKTAG('T', 'M', 'A', 'V')
40 
41 typedef struct TMVContext {
42  unsigned audio_chunk_size;
43  unsigned video_chunk_size;
44  unsigned padding;
45  unsigned stream_index;
46 } TMVContext;
47 
48 #define TMV_HEADER_SIZE 12
49 
50 #define PROBE_MIN_SAMPLE_RATE 5000
51 #define PROBE_MAX_FPS 120
52 #define PROBE_MIN_AUDIO_SIZE (PROBE_MIN_SAMPLE_RATE / PROBE_MAX_FPS)
53 
54 static int tmv_probe(const AVProbeData *p)
55 {
56  if (AV_RL32(p->buf) == TMV_TAG &&
58  AV_RL16(p->buf+6) >= PROBE_MIN_AUDIO_SIZE &&
59  !p->buf[8] && // compression method
60  p->buf[9] && // char cols
61  p->buf[10]) // char rows
62  return AVPROBE_SCORE_MAX /
63  ((p->buf[9] == 40 && p->buf[10] == 25) ? 1 : 4);
64  return 0;
65 }
66 
68 {
69  TMVContext *tmv = s->priv_data;
70  AVIOContext *pb = s->pb;
71  AVStream *vst, *ast;
72  AVRational fps;
73  unsigned comp_method, char_cols, char_rows, features;
74 
75  if (avio_rl32(pb) != TMV_TAG)
76  return -1;
77 
78  if (!(vst = avformat_new_stream(s, NULL)))
79  return AVERROR(ENOMEM);
80 
81  if (!(ast = avformat_new_stream(s, NULL)))
82  return AVERROR(ENOMEM);
83 
84  ast->codecpar->sample_rate = avio_rl16(pb);
85  if (!ast->codecpar->sample_rate) {
86  av_log(s, AV_LOG_ERROR, "invalid sample rate\n");
87  return -1;
88  }
89 
90  tmv->audio_chunk_size = avio_rl16(pb);
91  if (!tmv->audio_chunk_size) {
92  av_log(s, AV_LOG_ERROR, "invalid audio chunk size\n");
93  return -1;
94  }
95 
96  comp_method = avio_r8(pb);
97  if (comp_method) {
98  av_log(s, AV_LOG_ERROR, "unsupported compression method %d\n",
99  comp_method);
100  return -1;
101  }
102 
103  char_cols = avio_r8(pb);
104  char_rows = avio_r8(pb);
105  tmv->video_chunk_size = char_cols * char_rows * 2;
106 
107  features = avio_r8(pb);
108  if (features & ~(TMV_PADDING | TMV_STEREO)) {
109  av_log(s, AV_LOG_ERROR, "unsupported features 0x%02x\n",
110  features & ~(TMV_PADDING | TMV_STEREO));
111  return -1;
112  }
113 
116  if (features & TMV_STEREO) {
117  ast->codecpar->channels = 2;
119  } else {
120  ast->codecpar->channels = 1;
122  }
124  ast->codecpar->bit_rate = ast->codecpar->sample_rate *
126  avpriv_set_pts_info(ast, 32, 1, ast->codecpar->sample_rate);
127 
128  fps.num = ast->codecpar->sample_rate * ast->codecpar->channels;
129  fps.den = tmv->audio_chunk_size;
130  av_reduce(&fps.num, &fps.den, fps.num, fps.den, 0xFFFFFFFFLL);
131 
135  vst->codecpar->width = char_cols * 8;
136  vst->codecpar->height = char_rows * 8;
137  avpriv_set_pts_info(vst, 32, fps.den, fps.num);
138 
139  if (features & TMV_PADDING)
140  tmv->padding =
141  ((tmv->video_chunk_size + tmv->audio_chunk_size + 511) & ~511) -
142  (tmv->video_chunk_size + tmv->audio_chunk_size);
143 
144  vst->codecpar->bit_rate = ((tmv->video_chunk_size + tmv->padding) *
145  fps.num * 8) / fps.den;
146 
147  return 0;
148 }
149 
151 {
152  TMVContext *tmv = s->priv_data;
153  AVIOContext *pb = s->pb;
154  int ret, pkt_size = tmv->stream_index ?
156 
157  if (avio_feof(pb))
158  return AVERROR_EOF;
159 
160  ret = av_get_packet(pb, pkt, pkt_size);
161 
162  if (tmv->stream_index)
163  avio_skip(pb, tmv->padding);
164 
165  pkt->stream_index = tmv->stream_index;
166  tmv->stream_index ^= 1;
167  pkt->flags |= AV_PKT_FLAG_KEY;
168 
169  return ret;
170 }
171 
173  int64_t timestamp, int flags)
174 {
175  TMVContext *tmv = s->priv_data;
176  int64_t pos;
177 
178  if (stream_index)
179  return -1;
180 
181  pos = timestamp *
182  (tmv->audio_chunk_size + tmv->video_chunk_size + tmv->padding);
183 
184  if (avio_seek(s->pb, pos + TMV_HEADER_SIZE, SEEK_SET) < 0)
185  return -1;
186  tmv->stream_index = 0;
187  return 0;
188 }
189 
191  .name = "tmv",
192  .long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"),
193  .priv_data_size = sizeof(TMVContext),
199 };
#define NULL
Definition: coverity.c:32
Bytestream IO Context.
Definition: avio.h:161
Definition: tmv.c:41
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4882
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:153
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3953
int num
Numerator.
Definition: rational.h:59
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:246
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:331
static int tmv_read_header(AVFormatContext *s)
Definition: tmv.c:67
static AVPacket pkt
#define AV_CH_LAYOUT_STEREO
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:87
#define PROBE_MIN_SAMPLE_RATE
Definition: tmv.c:50
Format I/O context.
Definition: avformat.h:1358
AVInputFormat ff_tmv_demuxer
Definition: tmv.c:190
static int tmv_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: tmv.c:150
int width
Video only.
Definition: avcodec.h:4019
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
static int tmv_probe(const AVProbeData *p)
Definition: tmv.c:54
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4455
Definition: tmv.c:36
#define AVERROR_EOF
End of file.
Definition: error.h:55
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:310
int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max)
Reduce a fraction.
Definition: rational.c:35
uint64_t channel_layout
Audio only.
Definition: avcodec.h:4055
#define av_log(a,...)
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: avcodec.h:3982
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1509
unsigned padding
Definition: tmv.c:44
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:770
static int tmv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: tmv.c:172
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
unsigned audio_chunk_size
Definition: tmv.c:42
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3949
#define TMV_TAG
Definition: tmv.c:39
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1483
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:639
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
audio channel layout utility functions
unsigned video_chunk_size
Definition: tmv.c:43
#define TMV_HEADER_SIZE
Definition: tmv.c:48
#define s(width, name)
Definition: cbs_vp9.c:257
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
Stream structure.
Definition: avformat.h:881
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
#define PROBE_MIN_AUDIO_SIZE
Definition: tmv.c:52
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:468
Rational number (pair of numerator and denominator).
Definition: rational.h:58
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
#define flags(name, subs,...)
Definition: cbs_av1.c:561
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
int sample_rate
Audio only.
Definition: avcodec.h:4063
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:754
Main libavformat public API header.
int den
Denominator.
Definition: rational.h:60
void * priv_data
Format private data.
Definition: avformat.h:1386
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:3995
int channels
Audio only.
Definition: avcodec.h:4059
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:358
int stream_index
Definition: avcodec.h:1479
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
#define AV_CH_LAYOUT_MONO
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
This structure stores compressed data.
Definition: avcodec.h:1454
unsigned stream_index
Definition: tmv.c:45